Influence of presowing gamma – irradiation of amaranth seeds on the frequency of mitotic disorders in root meristem

Abstract

Studies of mitotic activity, frequency and range of chromosomal aberrations in cells of root meristem in the first post-irradiation mitotic cycles enable us to reliably assess levels of primary damage in the genetic system and activity of repairing processes.

The aim and tasks of the study. The purpose was to study effects of various doses of gamma- rays on the frequency of mitotic disorders in root meristem of different amaranth varieties.

The objectives were to determin the optimum temperature for germination of amaranth seeds and to select a dye for staining amaranth roots.

Materials and methods. Three amaranth varieties were used in the research: Students, Kharkov -1 and Sem gamma-irradiated at the doses of 15 Gy, 30 Gy, 40 Gy, 150 Gy, 400 Gy and 700 Gy. The anaphase method was used to determine the frequency of mitotic disorders.

Results and discussion. In general, the frequency of mitotic disorders in amaranth root meristem after gamma-irradiation of Students, Kharkov – 1 and Sem varieties significantly varied. The varieties differed by the fragment and bridge numbers in cells, which were higher as  doses of mutagen increased.

For example, 15 Gy of Students caused resulted in nine cells with disorders (five with bridges and four with fragments), and in Sem variety after exposure to the same dose eight damaged cells were found (three with fragments and  five with bridges).

Conclusions. Thus, the research revealed that the varieties of amaranth, A. hуpochondriacus, (Sem, Kharkov -1 and Students) were susceptible to gamma-rays. The research showed that the higher dose of gamma-rays was, the higher the frequency of chromosomal abnormalities became. 400 Gy and 700 Gy were lethal to amaranth. After 150 Gy, the percentage of disorders increased from 6.7% to 7.7% in Sem variety and in Kharkov - 1 variety.